Soooooo,

it’s a 1969, L46. The original engine is long gone. So I decided to replace it with a modern, ‘homage’ engine. A 400SBC, RPC aluminum heads, 11.0:1

The cam is compcam Xtreme Energy Hydraulic Roller 12-422-8

https://www.summitracing.com/parts/CCA-12-422-8

the DD2000 is:




It was designed to replicate the L-46 and then some. Which is does tremendously well. Vacuum is at 20 inches.

I have two problems with this cam. The off ramps are very aggressive leaving me with very noisy valve action. The valves are clacking away as the slam shut.

And secondly, low and mid are great, but it makes me drive it like a lazy man. It runs out of steam in my the 4000RPM range. (Manual) I think I need a bump to my bump stick and more
power in top end.

Is there something out there that would give me that and still enough vacuum to run my lights and wiper door ??

TBH, I was spoiled by my centrifugally supercharged 400 (previous ride). It made way north of 600. I guess I just need more.

MTIADC3

 

This would be a good cam that would work well in your 400.....it would have a nice lumpy (not rough) idle great mid range and work well on the street.
https://www.howardscams.com/hydrauli...cams-110255-10

If you want a smoother idle then you could use this one with a wider lobe separation.
https://www.howardscams.com/hydrauli...cams-110255-12

I have a Crower cam in my 400 with almost the same specs as above, but a 108 LSA and find the idle a little too rough as I get older....LOL

 

I rarely say this but I think your cam is too small for a 400. I'm running the next size bigger Xtreme Energy HR (224/230) and it pulls all the way to 6000 in my 350.

 

If you can find it or are patient, this cam could be a possibility.

http://www.pbm-erson.com/Catalog/Ers...r_E/ERSE119847

 

I should have also prefaced. I’m 52. With age, too lumpy is less desirable.

 

There is a compromise I suppose is my wiper door and headlights still need to operate.

 

The Erson cam is on a 112 lobe separation and 66 degree of overlap. Not a whole lot of lumpy.

 

Agree with the posters above. Your 214 dur @ .050 is way mild, and has a low rpm HP peak.
230 dur is about the limit for a nice street cam. As long as you keep the lobe center at 110 or 112, it will idle OK and make decent vac. Stay away from the tight 106-108 LC if you want idle vac. Just a little more dur or less LC and it gets tempermental in a hurry. That's OK if that's what you want. The extra 16 degrees duration will make it pull hard to near 6k. Probably peak at 5600 vs the 4400 you have now.

My 230/240 cam made 15 inches of vac at an 850 idle in a 454. with a 110 lobe center.
Plenty for the vac system.
And it goes higher when you drive it anyway. That's just at idle.
Here is what mine sounded like on the Dyno FYI:

 

The second cam here is a great choice.......this should raise the peak about 1000rpm and add about 60 horsepower.....use with 1.6 rockers if you have the clearance......

Jebby

 

I just need to add that with the cam I have now (230/232 @50 and .550" lift ) and a 108 LSA I have no vacuum issues with power brakes or headlights.
I get 11" vacuum IIRC.

 

I am also running the same cam as Crimson(XR276hr) and am pretty happy with it. It sounds mean at idle and it picks up pretty good. I would suggest a minimum of a 750cfm carb which is usually standard on a Rochester. Keep in mind cam must match up your cylinder heads. I have the 64cc heads with the 2.02 valves.

 

Im running the OP's cam in my 355 with no complaints but I imagine its effectively a size or 2 smaller in a 400.. I also have an automatic so its only hit 5000rpm a couple of times. That said as ive been researching parts to gather for a 406 build, based on what ive read so far I also am planning on going to the 276 equivalent.

 

Been researching my combination of lifters and cam. It seems like I’m double screwed. The comp cam has aggressive off ramps and the lifter also have issues. I saw some reviews - consensus is noisy and they leak down. That’s expensive to replace all that.

 

 

.050 duration numbers are way more important than advertised #s. Intake dur determines your basic rpm. Unfortunately you did not mimic the 224 degree L46 cam, you chopped duration by 10 degrees. Every 10 degrees gives you about 700 rpm or so. And there is some more variation for the extra cubic inches, the extra cubic inches flow the same airflow at a lower rpm, so that cost you another 12% or 700 rpm, hence your dis-satisfaction.

So your plan to increase the duration by 20 degrees is a good one. 214 + 20 yields 234. You're basically right on. Should rev/drive similar to the L46 cam, but in a 400.
The extreme cams do have very fast ramps, and yes that causes issues. I am not a fan. They are much fussier with parts selection, for not a lot of advantage. The Magnums have the old school slower ramps. So do the Howards. Better choice, and should be less noisy.

Now if you want a HR lifter motor to rev very well, to 6000 without pump-up, you are going to need some very good lifters. 6000 rpm is kind of their limit where a lot of them start having a hard time keeping up. I do not recall you mentioning what kind you have, but fast ramps require extremely good lifters to be able to avoid the noise. Quality cost money here. I would suggest doing some research here carefully to avoid more issues in the future. Don't forget the springs have to be carefully matched to both the cam, the rpm and the lifters. A 6000 rpm HR motor is not hard, but it won't work well with bargain parts, it needs some quality parts selection.

I would suggest some good quality springs designed for 6000+ rpm, and those will require some very good quality Hyd rollers. Then you will be very happy with a 230 ish Magnum cam or similar and it will buzz 6500 rpm easily if you want. HP will be waay up, like +100-150 or more. 460-480-500 depending on how good your heads and induction are.

A 108 LC with that duration will kill your vacuum, a 112 LC will keep enough to do what you want.

Good luck.

 

dorian,
What lifters are you running now if you dont mind me asking? Im running enginetech retro roller lifters I bought on rock auto a couple years ago for like $130 for the set... They are noisier than my old voodoo flat tappet setup for sure.

 

Hydraulic rollers make some valvetrain noise but it is what I consider "good noise"....like a solid.......as long as the song remains the same (shameless Zep reference)....the noise is music......
But...where is your lash? 1/2 turn? Not enough lash makes them noisy......
I stopped using Comp and went to Howard's about ten years ago....just too many issues overall with several different things......Howard's applies the KISS principle....and I like that. I stopped using the X-Treme Comp grinds in a flat tappet when lobes started grinding away due to accelerated ramp profile......and the fact that the Magnum grinds made just as much power everywhere and sounded better......those are the only two cams I still use from Comp, the 280H and 292H Magnum........I have a Custom 292H Magnum flat tappet in my own 406 ground on a 108 LSA.......it pulls hard and revs free......
Also...do you have a premium .080 wall pushrod in there? A flexy pushrod can make noise on aggressive ramps......

Jebby

 

I cant speak for the OP but I do have crower branded push rods now but it sounded the same with the cheap elgin ball tip pushrods I had before honestly.

 

Running these

 

First of all why do you think that you will have 11:1 compression? What are the specs on your heads and what intake? I'm from the show me state and I'm very skeptical when somebody says something. Then we can discuss what I know works in roller cams and keeping DCR in the picture. Never ask someone that does NOT own or build roller cam motors for advice! Don't ask a person who owns a 350 flat cam for advice on a 400 roller. Many of the above posters listed cams that will NOT run on pump gas. Serious detonation problems.

All my vacuum items worked great down to the 12 inch level at idle. I ran 383 and 396 ci sbc's in my vette since the early 90's both with around 11:1